MRI Features Of Autoimmune Encephalitis And Cortical Morphological Changes In Anti-N-Methyl-D-Aspartate Receptor Encephalitis And Their Correlation With Clinical Scores

Objective:The imaging characteristic of autoimmune encephalitis?AE?is analyzed to improve understanding of this disease.And to investigate the value of Freesurfer technology in the cortical morphology in patients with Anti-N-methyl-D-aspartate receptor?NMDAR?encephalitis and to further study the correlation between the changes in cortical thickness,volume and deep gray matter volume and the scores of modified Rankin scale?mRS?and cognitive scale.Method:A total of 108 AE patients diagnosed by the Department of Neurology of the First Affiliated Hospital of Chongqing Medical University from October 2012 to October 2018 were divided into NMDA group?66 cases?and non-NMDA group?42 cases?.All patients underwent brain MRI scanning within 1 week after admission,and 48 patients with anti-NMDA receptor encephalitis received brain MRI review within 4-6months after discharge.The signal,distribution and enhancement of the lesions were observed.And 40 age,gender and education matched healthy control groups?HC?were carried in our study.All subjects underwent conventional MRI and whole-brain high-resolution 3D-T1WI.Freesurfer software was used to analyze the differences in cortical thickness,volume and deep gray matter volume between the two groups,and the correlation analysis between cortical morphology abnormalities and the scores of mRS and cognitive scale was performed.Results:?1??1?Four cases of ovarian teratoma and one case of mediastinal teratoma occurred in patients with anti-NMDAR encephalitis,and three cases of small cell lung cancer?SCLC?occurred in patients with anti-GABA_BR encephalitis.?2?The top three clinical symptoms were,in order,mental and behavior disorder,epilepsy,and involuntary movement.The rates of fever and involuntary movement in the NMDA group were higher than that in the non-NMDA group,while the rates of language disorder,epilepsy and consciousness disorder in the NMDA group with were lower than that in the non-NMDA group.?3?During the first MRI examination,34 patients showed lesions in multiple brain areas on conventional MRI plain scan.Lesions of anti-NMDAR encephalitis mainly located in the non-limbic system,while lesions in the non-NMDA group mainly located in the limbic system.Most of the lesions were isointense,slightly hypointense or hypointense on T₁WI and slightly hyperintense or hyperintense on T₂WI and FLAIR.After enhancement,10 patients showed meningeal enhancement,focal vascular thickening,and focal patchy enhancement.?4 Reexamination of MRI in 48 patients with anti-NMDAR encephalitis showed that the lesions disappeared in 5 patients,new lesions appeared in 1 patient,and brain atrophy in 11 young patients.?2??1?Adjusting for age,education and disease duration,compared with HC group,the cortical thickness of patients reduced significantly in the left superior temporal gyrus,left middle temporal gyrus and left fusiform?CWP<0.05?.The cortical volume decreased significantly in the right lateral occipital cortex?CWP<0.05?.The bilateral hippocampus and right thalamus decreased significantly?CWP<0.05?.?2?Correlation analysis results showed that cortical thickness in the right temporal cortex?superior temporal gyrus,middle temporal gyrus,fusiform gyrus?was positively correlated with MMSE scores?r=0.507,r=0.572,r=0.602,all P<0.05?.The left medial temporal gyrus was significantly correlated with AVLT-DR scores?r=-0.533,P<0.05?.The cortical thickness in left fusiform was positively correlated with SDMT scores.Bilateral hippocampal volume was significantly correlated with MMSE scores?r=0.542,r=0.445,both P<0.05?.There was no significant correlation between cortical volume and cognitive score?P>0.05?.?3?There was no significant correlation between cortical thickness,cortical volume,deep gray matter volume and disease severity?mRS scores?.Conclusions:?1?Anti-NMDAR encephalitis can involve multiple cortical brain regions,and the other subtypes of AE involved the limbic system,which was dominated by hippocampus.?2?FLAIR sequence is an important sequence to observe the disease,and latent lesions that cannot be detected by conventional MRI can be found on DWI.?3?Thinner cortical thickness,reduced cortical volume and decreased deep gray matter volume were indicated in anti-NMDAR encephalitis during a later stage of the disease,and the cortical thickness and deep gray matter volume in some brain regions are associated with cognitive dysfunction in patients.